So, some 120 UK-based millionaires – including football pundit Gary Lineker, crime writer Val McDermid, screenwriter/director Richard Curtis, and at least 100 people you’ve never even heard of – have generously written to newbie prime minister Andy Burnham, urging him to tax them more. And they claim they represent 75% of the UK’s millionaires.

Which is nice of them. Even if we can only guess how and why most of these generous souls became a millionaire in the first place.

Unfortunately, the millionaires don’t say how – or by how much – Andy Burnham should tax them more. And, as noted previously on this blog, we know that wealth taxes are problematic.

But I have a proposal. I suggest Andy Burnham creates a voluntary wealth tax, for millionaires – and even billionaires – who believe they should pay more tax. This would avoid the (significant) problems of asset valuation, collection and enforcement associated with most wealth tax proposals. And, simply by publishing the amount of extra tax voluntarily paid by each resident millionaire and billionaire, the public could assess the genuineness of their stated desire to pay more tax.

They say they can afford it. So, let’s allow the self-declared “super rich” to put their tax returns where their mouths are. Over to you, Gary Lineker.